Anti-pick tumbler lock device

ABSTRACT

This disclosure is directed to a tumbler lock having relatively movable lock members and associated locking pins or tumblers which are required to be displaced a predetermined amount to permit relative movement between the complementary locking members in which there is operatively connected to one of the relatively movable lock members a biasing member for imparting a limited biasing force on the movable lock member to resist initial movement of the movable lock member toward the open position of the lock to prohibit a would-be lock picker from setting up the lock pins and picking the lock.

United States Patent 1191 1111 3,733,864

Greenwald 14 1 May 22, 1973 [54] ANTI-PICK TUMBLER LOCK DEVICE 1,494,765 5 1924 Barrett ..70/DIG. 32 Inventor: Harry Greenwald whitestone, NY. 3,656,328 4/1972 Hughes ..70/364 A X [73] Assignee: Walter Kidde & Company, Inc., Primary Examiner-Albert G. Craig, Jr.

Clifton, NJ. Attorney-Seidman & Fisher [22] Filed: Apr. 14, 1971 [57 ABSTRACT 21 App]. No.: 133,831

This disclosure is directed to a tumbler lock having relatively movable lock members and associated 1 CL 32 locking pins or tumblers which are required to be dis- [5 l] Int. Cl. ..E05b 27/10 placed a predetermined amount to permit relative [58] Field of Search ..70/DlG. 32, DIG. 36, movement between the complementary locking mem- 200/44 bers in which there is operatively connected to one of r the relatively movable lock members a biasing References Cited member for imparting a limited biasing force on the movable lock member to resist initial movement of the UNITED STATES PATENTS movable lock member toward the open position of the 3,358,093 12/1967 Cryer .200/44 lock to prohibit a would-be lock picker from setting up the lock pins and picking the lock. 1,288,074 12/1918 3,339,384 9/1967 Greenwald ..70/363 11 Claims,8Drawing Figures 1 I 5: l 'l' 1 1 H 45 '1 i 36 e 4'- 1 8 37 54151;; t I 1 "J ANTI-PICK TUMBLER LOCK DEVICE PROBLEM AND PRIOR ART Heretofore tumbler locks of the type to which this invention relates were vulnerable to picking. For this reason operators of coin-operated machines and/or vending machines secured by such tumbler lock constructions have suffered considerable amount of loss as a result of the skill which certain unscrupulous persons have developed in picking tumbler type locks. In the past these lock pickers have been successful in picking tumbler locks, as used on coin operated machines, because they were able to develop a sense of touch by which they could sense when the lock pins have been displaced an amount sufficient to render the lock operative. The technique adopted by these lock pickers was to maintain the respective lock pins set by applying a torque on the lock member until all of the lock pins had been set. By doing this the lock picker could easily set the respective lock pins so as to render the lock operative without a key. Generally the movement provided by the working tolerance of the component lock parts was sufficient to permit the picker to set one or more of the lock pins. By successfully performing operations a number of times the picker could eventually set each lock pin so that the lock was finally rendered operative. Such unscrupulous pickers have been able to develop this unlawful skill in picking such locks solely because the known constructed locks permitted the picker to set and maintain the movable lock at the socalled break position as each lock pin is set.

OBJECTS It is therefore an object of this invention to provide a tumbler lock device in which the movable lock member is biased in a manner to resist initial movement thereof toward open position so as to prohibit the setting up of the code pins by a would-be lock picker.

Another object of this invention is to provide a tumbler lock with an anti-pick mechanism which operates on the lock members to desensitize the pickers feel in setting the lock pins.

Another object of this invention is to provide a tubular lock with an anti-pick device which can be readily adapted to existing locks, and which is relatively simple in construction, positive in operation and inexpensive to manufacture.

Another object of this invention is to provide a tumbler lock having cooperating camming members constructed and arranged so as to impart a limited biasing force on the lock members which tend to resist the initial movement of the lock member in moving from closed to open position.

Another object is to provide a tumbler lock with an anti-picking device which is connected to the movable lock member and rendered operatively associated with a cam which, when rendered operative, functions to mitigate a would-be pickers sense of feel in setting up the tumbler during a lock picking attempt.

BRIEF SUMMARY OF THE INVENTION The foregoing objects and other features and advantages of this invention are attained by a tumbler lock construction which is suitably supported on a wall portion or coin box ofa coin operated machine or the like. Generally the lock assembly comprises a lock housing suitably secured to a wall portion of a vending machine or the like, e.g., the front wall of a coin box. Disposed within the housing are a pair of relatively movable lock members. Each of the respective lock members is provided with a plurality of axially aligned bores for receiving a set of lock pins and associated code pins. The arrangement is such that the lock pins are mounted in the bore of one of the members which an end portion thereof extending into the corresponding bores of the other member. The associated code pins, which may be of varying length, are disposed in the respective bores of the other member so that the adjacent ends of the lock pins and the code pins are contiguously disposed. The arrangement is such that by the introduction of a proper key into the keyway of the lock means, the code pins are caused to be axially displaced a predetermined amount to effect displacement of the lock pins a corresponding amount so that the contiguous adjacent ends of the pins are moved into coincidence with the adjacent face portion of the relatively movable lock members so that relative movement between the respective lock members in open and closed position is permitted.

In accordance with this invention, to prohibit a would-be lock picker from setting up the respective lock pin by feel, a means is provided for imparting a biasing or counter-acting force on the movable member of the lock assembly. The arrangement is such that as the illegal picker tends to maintain the lock pin set by limited displacement of the lock member, by the technique described, the biasing means will cause the lock member to assume its normal position, thereby prohibiting the picker from maintaining the set.

The anti-lock means comprises a cooperating cam means in the form of a cam surface mounted on the supporting wall of the lock and an associated cam plate operatively connected to the movable lock member to rotate therewith. The cam plate is suitably secured to the movable member of the lock member so that when a would-be lock picker attempts to maintain the lock pin set by limited displacement of the lock member, the initial displacement of the lock member effects a simultaneous co-action between the cam plate and the cam surface to impart a force which counter-acts the displacement of the movable member. The counteracting force is such that it is rendered operative only when a would-be picker attempts to pick the lock. The arrangement is such that the biasing or counter-acting force can be completely overridden when a proper key has been inserted in the keyway of the lock and actuated to effect simultaneous displacement of the respective tumbler pins so that the movable member of the lock may be moved to effect the opening of the lock.

FEATURES A feature of this invention resides in the provision of a tumbler lock having cooperating camming members operatively associated with the movable member of the lock to impart a biasing or counter-acting force on the movable member to resist setting up of the lock pins by a would-be lock picker.

Another feature of this invention resides in a tumbler lock having an anti-,picking means in the form of a cam plate connected to the movable member which is cooperatively associated with a cam surface to maintain a biasing or counter-acting force on the movable member to deter lock picking.

Another feature of this invention resides in an antipicking device which can be readily incorporated to existing locks without effecting any substantial change in the construction of the lock per se.

Other features and advantages of this invention will become more readily apparent when considered in view of the drawings and specification in which:

FIG. 1 is a side elevation view of a tumbler lock embodying the invention having parts thereof shown in section.

FIG. 2 illustrates a rear end view of the lock assembly taken along line 22 on FIG. 1 when the lock is in a normal locked position.

FIG. 3 illustrates a view similar to that of FIG. 2 but illustrating the relative position of the parts when a lock picker attempts to set up the lock pins in attempting to pick the lock.

FIG. 4 is a view similar to that of FIGS. 2 and 3 but illustrating the relative position of the parts in the full open position of the lock.

FIG. 5 is a side elevation view of FIG. 4.

FIGS. 6, 7 and 8 illustrate detailed sectional views of a tumbler lock assembly to which the instant invention is applied.

Referring to the drawings, there is shown in FIG. 1 an assembled view of the tumbler lock assembly embodying the present invention. The tumbler lock assembly 20 is shown as applied to the coin box 21 of a coin operated vending machine (not shown). The illustrated coin box 21 is provided with an outer front wall 22 having a projecting boss portion 22A terminating in an opening 228 for receiving a tumbler type lock assembly 20. The tumbler lock 20 may comprise a lock of the type disclosed in US. Pat. No. 3,330,14ll. More specifically the lock assembly 20 comprises a tubular housing 23 having a front facing portion 23A terminating in an inturned flange 233 to define a front opening 25. Between the opposed ends of the housing 23 there is formed a bore 26 for containing the complementary lock parts 27 and 28 as will be herein described. The bore 26 terminates in an internal shoulder 26A that is spaced inwardly from the inturned flange 23B defining the front opening of the housing 23. One of the complementary parts within the bore 26 of the housing 23 is a plug member 27 having a head portion 27A and a connected stem portion 273, the latter being of reduced cross section. The head portion 27A is provided with an outer periphery which is sized so as to be received within bore 26 of the housing so that the front face of the head portion 27A is disposed in abutting relationship with the internal shoulder 26A of the housing. The arrangement is such that the plug member is rendered free to rotate within the bore 26 of the housing 23. Connected to the head end portion 27A of the plug member 27 is a key guide 29 for positioning a key 30 to effect the opening and closing of the lock 20.

The enlarged end portion 29A of the key guide 29 is provided with a circumference which is spaced from the circumference defined by the flange 23B forming the front opening 25 of the housing 23. The annular space thus defined between the exterior circumference of the head 29A of the key guide 29 and the inner circumference of the inturned flange 23B defines a key opening for receiving the key 30.

The inturned flange 23B defining the front opening 25 of the housing is provided with a notch 31 adapted to receive a lug formed on the key 30 for effecting the alignment between the key 30 and the keyway.

An annular pipe member or ring 28 is mounted on the stem portion 278 of the plug 27 within the tubular housing 23. The arrangement is such that the front facing of the annular pipe member 28 is disposed contiguous to the head portion 27A of the plug 27. The annular pipe member 28 in turn is fixed against relative rotation with respect to the housing 23 by means of a set screw 23 which is threaded through a tapped opening formed in the wall portion of the housing 23. The annular pipe member 28 is provided with a plurality of circumferentially spaced bores 33 extending longitudinally therethrough.

A washer 34 is positioned on the stem 27B of the plug member 27 contiguous to the rear facing of the pipe member 28 to form a base or bottom for the bores 33 extending through the pipe member. A retainer ring 35 suitably secures the annular pipe member 28 and associated washer 34 in position on the stem 27B of the plug member 27.

The extended end portion 27C of the stem 27B is threaded for receiving a suitable lock nut 36. The lock assembly in turn is secured to the front wall of the coin box by a lock nut 37 threaded to the housing 23, as best seen in FIG. 1.

The head end portion 27A of the plug member 27 is also provided with a plurality of longitudinally extending bores 38. As shown in FIG. 6 the bores 38 of the head 27A are disposed in axial alignment with the bores 33 of the pipe member 28 in the locked position of the lock. Suitable lock pins 39 are disposed in each of the bores 33 of the pipe member 28 and are normally maintained under spring bias by means of a spring 40, as seen in FIGS. 6 and 7. The arrangement is such that the spring 40 normally tends to exert a force on the lock pins 39 tending to urge the lock pins 39 out of the plug member. Positive retention of the lock pins 39 within the bores 33 may be accomplished by providing the bore with an internal shoulder, as by counterboring, and providing the; lock pins with a complementary flange adapted to abut against the shoulders so formed. Accordingly the ends of the respective lock pins 39 projecting through the bore 33 of the pipe member 28 and into the aligned bores 38 of the plug member 27 serve to prohibit relative rotation between the plug member 27 and the annular pipe member 28 in the locked position.

Disposed within each of the aligned bores 38 of the head portion 27A are code pins 42. It will be noted that the code pins 42 are of varying lengths. The arrangement is such that each code pin 42 is required to be set, or axially displaced a predetermined amount so that each of the cooperating lock pins are axially displaced a corresponding amount. When properly set the adjacent abutting end portion of the respective lock pins 39 and code pins 42 are disposed in alignment with the respective contiguous face portions of the head end portion 27A of the plug member 27 and the annular pipe member 28. Accordingly, rotation of the plug member 27 relative to the pipe member 28 can be effected only upon turning the key when the abutting ends of pins 39 and 42 are disposed in alignment with the contiguous face members or break point of the lock members 27 and 28.

To deter setting up the lock pins 39 at their break point" by a would-be picker the present invention contemplates the utilization of a means for maintaining a bias of counteracting force on the movable lock member 27. As best seen in FIGS. 1 and 6 the threaded end portion 27C of the lock member 27 is extended through the inner wall 43 of the coin box 21 and has connected to the end thereof a cam plate 44. The cam returns the locking member to its operative lock posiplate 44 is suitably secured to the extended end 27C of 5 the movable lock member 27 so as to rotate therewith whenever the lock member 27 is rotated, and lock nut 45 secures the cam plate 44 in position on the stem portion 27C of the plug member 27.

As best seen in FIGS. 2, 3 and 4 the cam plate is provided with an elongated slot 46 which is adapted to engage in camming relationship with a cam surface 47 secured to the inner wall 43 of the coin box.

As best seen in FIGS. 1, 2, 3 and 4 the cam surface 47 is illustrated in the form ofa rivet head having a curvilinear surface which defines the cam surface. The width W of the slot 46 is made slightly less than the diameter of the cam surface or rivet head 47. The arrangement is such that the edges of the cam slot 46 will tend to ride on the surface of the rivet head when the lock member 27 and connected cam plate is rotated.

As best seen in FIG. 1, it will be noted that since the Width W of the slot 46 is less than the diameter of the rivet head 47, that a slight flexing of the cam plate 44 will occur as the cam plate is rotated relative to the fixed cam surface or rivet head 47. Since the cam plate 44 is formed of a material having some inherent resiliency, the operation is such that rotation of the plug 27 and associated cam plate 44 imparts a biasing or counteracting force on the plug member which is opposite to the opening movement of the plug member 27.

As best seen in FIG. 3, the co-action between the cam plate 44 and the cam surface 47 is such that whenever a would-be picker attempts to effect limited rotation of the movable member 27 to set up a lock pin at the break point," difficulty will be encountered by the picker to maintain the movable member at the break point due to the inherent resiliency of the cam plate 44 operating on the cam surface which sets up a biasing force which tends to effect rotation of the plug member toward its neutral or locked position. Consequently the camming action between the slot 46 of the cam plate 44 and the cam surface 47 is such that the slope of the curve of the cam surface will normally cause the cam plate and associated plug member 27 to be rotated clockwise as viewed in FIG. 3 and against the opening direction of the lock as a would-be picker attempts the set up of lock pins 39. Consequently the construction and the co-action between the cam plate 44 and the cam surface 47 is such that the would-be pickers sense of feel is interfered with, causing considerable difficulty in any attempt to set up the lock pins by the feel or lock pin set-up technique developed by such unscrupulous lock pickers.

The springlike bias which the cam plate 44 maintains on the movable lock member 27 when attempts are made to set up the lock pins 39 virtually frustrates such attempts.

However, whenever a duly authorized key is inserted into the keyway so that all of the lock pins are properly displaced, the arrangement is such that in effecting r0- tation of the movable member 27 from closed to fully open position, cam slot 46 of the cam plate can effectively override the cam surface 47, as seen in FIG. 4, permitting the lock to be actuated to a fully open position, and to be maintained in such open position until such time that the key rotated in the opposite direction tion.

As seen in FIG. 1, an eccentric locking cam 48 is interposed intermediate the end of the stem 27B to rotate therewith to activate the cooperating catches 49 in the form of sliding plate members disposed in sliding relationship between the outer and inner walls 27 and 43 of the coin box 21. Consequently whenever a proper key 30 is fitted into the keyway of the lock and rotated the movable member 27, camming plate 44 and locking cam 48 rotated in a counterclockwise direction as seen in FIGS. 2, 3 and 4 causing the cam plate 44 to successfully override the cam surface 47 to effect the opening of the lock. However, when a would-be picker attempts to pick the lock by setting up the lock pins by a limited or slight controlled movement of the locking member in a counterclockwise direction, as seen in FIG. 3, the cam plate co-acting with the cam surface 47 creates a counterbalancing force which urges the movable member 27 to its initially locked position. Consequently the movable member 27 will tend to automatically return to its locked position each time a would-be thief attempts to set up the lock pins.

In accordance with this invention the amount of the biasing or counteracting force which the camming member 44 may impart to the movable member of the lock may be adjusted by providing one or more shim washers 51 between the cam plate 44 and the inner wall 43 of the coin box 21. Consequently the arrangement is such that when one or more such shim washers are interposed on the extended stems 27C of the plug member 27 between the inner wall of the coin box and the cam plate, the inherent resiliency of the cam plate is proportionally decreased as the flexing resulting from he the action of the cam plate is reduced proportion ally.

While the cam plate 44 in the illustrated form of the invention, is illustrated as comprising a disc-shaped member it will be understood that a segmental portion of a disc may be utilized in lieu thereof. Also in lieu of a cam slot 44 as shown in FIGS. 2 to 4 it will be understood that an indentation to simulate a slotted indentation may be utilized in lieu of the slot.

In operation the co-action between the cam means 44 and the surface means 47 is such that it will adversely effect and interfere with the feel developed by a would-be picker in attempting to successfully set up the tumblers or lock pins to pick the lock.

To further deter other acts of theft a guard 54 may be connected to the outer wall 22 of the coin box or support for the lock assembly 20. As shown the guard 54 circumscribes the lock assembly. The co-action between the guard and the lock assembly is of the type described in U.S. Pat. Nos. 3,494,159; 3,444,712; and 3 ,334,501 wherein the front of the guard is formed with a key shaped opening which permits only an authorized shaped key to be fitted in the keyway of the lock.

While the instant invention has been described with respect to a particular embodiment thereof it will be readily understood and appreciated that variations and modifications of the invention may be made without departing from the spirit or scope thereof.

What is claimed is:

I. In combination, a tumbler lock assembly having a housing and relatively movable members, disposed within said housing, said members including a pipe member and a cooperative plug member movable relative thereto, each of said members having axially aligned bores formed therein, and associated lock pins and code pins disposed in said axially aligned bores formed in'said members, and a support means including a wall portion for supporting the housing of said lock assembly thereon,

the improvement comprising:

complementary camming means having a first member connected to said plug member and a second member connected to the wall portion of said support means for exerting a biasting force on said relatively movable members to offer predetermined limited resistance against relative movement between said members during initial movement thereof toward open position of said lock.

2. The invention as defined in claim 1 wherein said lock members are mounted for relative rotational movement and said first member of said complementary means comprising:

a cam detent connected to the wall portion of said support means, and said second member comprising a cam plate connected to said plug member whereby initial relative rotation of said lock member effects movement of said cam plate relative to said cam detent to maintain a biasing force for imparting a limited counter rotationaly resistance to the relative rotation of said lock members as said lock members are actuated from closed to open position a predetermined amount.

3. In combination,

a receptacle having a wall portion,

a lock assembly mounted on said wall portion,

said lock assembly including a housing supported on said wall portion,

a plug member rotatably disposed within said housing,

a pipe member fixed in said housing,

each of said members having a plurality of axially aligned bores formed therein,

a lock pin mounted in each bore on one of said members having one end thereof normally disposed to extend into the aligned bores of said other member,

a code pin disposed in each bore of said other memher whereby the code pins are in contiguous relationship to the ends of said lock pins for effecting axial displacement of said lock pins within their respective bores a predetermined amount to permit relative movement between said members when the ends of the lock pin have been displaced to an unlocking position,

and cooperating cam means associated with said lock assembly for imparting a counter-rotating torque on said plug member during initial rotation of said plug in movement from lock to open position, said cooperating cam means including:

a detent having an inclined cam surface mounted on said wall portion,

and a friction cam connected to said plug member to rotate therewith when said members are rotated between an open and locked position of said assembly.

4. The invention as defined in claim 3 and including means to adjust the counteracting force of said camming means.

S. The invention as defined in claim 3 and including means to adjust the amount of counter rotating torque imparted to said plug member.

6. The invention as defined in claim 3 wherein said friction cam includes means co-acting with said cam surface for imparting a biasing force on the associated plug member to resist initial rotation thereof when the lock assembly is actuated.

7. The invention as defined in claim 6 wherein said cam includes a plate member of spring material connected to said plug member disposed in camming relationship to said detent.

8. The invention as defined in claim 6 wherein said latter means includes an elongated slot formed in said cam, said slot having a width which is less than the width of said cam surface.

9. The invention as defined in claim 8 wherein said cam surface comprises a curvilinear surface.

10. The invention as defined in claim 8 wherein said cam surface comprises a rounded rivet head.

11. The invention as defined in claim 10 and including means for varying the biasing force of said cam. 

1. In combination, a tumbler lock assembly having a housing and relatively movable members, disposed within said housing, said members including a pipe member and a cooperative plug member movable relative thereto, each of said members having axially aligned bores formed therein, and associated lock pins and code pins disposed in said axially aligned bores formed in said members, and a support means including a wall portion for supporting the housing of said lock assembly thereon, the improvement comprising: complementary camming means having a first member connected to said plug member and a second member connected to the wall portion of said support means for exerting a biasting force on said relatively movable members to offer predetermined limited resistance against relative movement between said members during initial movement thereof toward open position of said lock.
 2. The invention as defined in claim 1 wherein said lock members are mounted for relative rotational movement and said first member of said complementary means comprising: a cam detent connected to the wall portion of said support means, and said second member comprising a cam plate connected to said plug member whereby initial relative rotation of said lock member effects movement of said cam plate relative to said cam detent to maintain a biasing force for imparting a limited counter rotationaly resistance to the relative rotation of said lock members as said lock members are actuated from closed to open position a predetermined amount.
 3. In combination, a receptacle having a wall portion, a lock assembly mounted on said wall portion, said lock assembly including a housing supported on said wall portion, a plug member rotatably disposed within said housing, a pipe member fixed in said housing, each of said members having a plurality of axially aligned bores formed therein, a lock pin mounted in each bore on one of said members having one end thereof normally disposed to extend into the aligned bores of said other member, a code pin disposed in each bore of said other member whereby the code pins are in contiguous relationship to the ends of said lock pins for effecting axial displacement of said lock pins within their respective bores a predetermined amount to permit relative movement between said members when the ends of the lock pin have been displaced to an unlocking position, and cooperating cam means associated wIth said lock assembly for imparting a counter-rotating torque on said plug member during initial rotation of said plug in movement from lock to open position, said cooperating cam means including: a detent having an inclined cam surface mounted on said wall portion, and a friction cam connected to said plug member to rotate therewith when said members are rotated between an open and locked position of said assembly.
 4. The invention as defined in claim 3 and including means to adjust the counteracting force of said camming means.
 5. The invention as defined in claim 3 and including means to adjust the amount of counter rotating torque imparted to said plug member.
 6. The invention as defined in claim 3 wherein said friction cam includes means co-acting with said cam surface for imparting a biasing force on the associated plug member to resist initial rotation thereof when the lock assembly is actuated.
 7. The invention as defined in claim 6 wherein said cam includes a plate member of spring material connected to said plug member disposed in camming relationship to said detent.
 8. The invention as defined in claim 6 wherein said latter means includes an elongated slot formed in said cam, said slot having a width which is less than the width of said cam surface.
 9. The invention as defined in claim 8 wherein said cam surface comprises a curvilinear surface.
 10. The invention as defined in claim 8 wherein said cam surface comprises a rounded rivet head.
 11. The invention as defined in claim 10 and including means for varying the biasing force of said cam. 